/*
Divide a given amount into bills and coins using a greedy algorithm.
This program is written in idiomatic Scala 3, using clear structure,
functions, built‑in methods, and full explanations.
*/
object DivideAmountApp:
/*
Function: divideAmount
----------------------
Given an amount and a list of bills/coins, prints how many
of each denomination are needed using a greedy algorithm.
The greedy method is optimal for standard currency systems.
*/
def divideAmount(amount: Int, denominations: List[Int]): Unit =
println(s"Dividing amount: $amount\n")
var remaining = amount
for d <- denominations do
val count = remaining / d // integer division
if count > 0 then
println(s"$d-unit: $count")
remaining %= d // reduce remaining amount
if remaining > 0 then
println(s"\nWarning: leftover amount = $remaining")
def main(args: Array[String]): Unit =
val bills_coins: List[Int] = List(500, 100, 200, 50, 20, 10, 5, 2, 1)
// Scala 3 descending sort (requires explicit `using`)
val denominations: List[Int] =
bills_coins.sorted(using Ordering[Int].reverse)
val amount: Int = 9749
divideAmount(amount, denominations)
/*
run:
Dividing amount: 9749
500-unit: 19
200-unit: 1
20-unit: 2
5-unit: 1
2-unit: 2
*/
